Switching mechanism



June 8, 1954 R. H. PETERSON ETAL 2,680,382

swrTcHING MECHANISM Filed Dec. 30. 1950 ya! 36 fdc a f6 ,La f6 za, c? l? c ze Z6 ze A'TTORNEY Patented June 8, 1954 SWITCHING MECHANISM Robert H. Peterson, Woodbury Heights, and Theodore E. Rolf, Collingswood, N. J., assignors to Radio Corporation of America, a corporation of Delaware Application December 30, 1950, Serial No. 203,644

9 Claims. (Cl. 711-483) Our present invention relates to switch mecha nsms and more particularly to multiple pushbutton switches.

There frequently arises a situation in which it has been found desirable to provide push-button means for switching electrical circuits either singly or in groups. An example of such a situation is an interofce communication system wherein it is frequently desirable to call a single party or to call several parties simultaneously as in a conference call. In addition, it is frequently important that such switching means be capable of withstanding considerable mechanical shock without interrupting the circuits that may be completed through the switch mechanism.

In conventional push-button switches there is provided an interlocking means whereby the depression of one push-button plunger releases a previously depressed plunger. In such switches, more than one plunger may be locked in the depressed position only by simultaneously depressing the selected plurality of plungers or by manually holding the previously depressed. plungers down while depressing additional selected plungers.

Further in conventional push-button switches, the plungers are held depressed by a single latch member. Although the latch member may be spring biased, a sudden jolt or jar may cause the single latch member to release the depressed plunger. Such a feature would be disadvantageous and, particularly when the switch is employed in mobile equipment, may frequently interrupt operation.

Accordingly, it is an object of our present invention to provide an improved push-button switch mechanism which obviates the above objectionable features.

It is another object of our present invention to provide an improved push-button switch mechanism which is characterized by shockproof latching of the switch plungers.

A further object of our present invention is the provision of an improved push-button switch as set forth in which means are provided for cumulatively latching a plurality of switching plungers.

It is still another object of our present inveni tion to provide a switch as set forth which may be released from a remote point.

In accomplishing these and other objects we have provided a push-button switch having a plurality of Contact operating plungers of substantially identical construction. A double acting latching means provides shockproof locking ofv the actuated sections. Individual, independent latching segments permit cumulative locking of the several switch plungers, all of which may be released by the operation of a single release button.

A better understanding of our present invention may be had from the following detailed description when read in connection with the accompanying drawings in which:

Figure 1 is a side view of a portion 0f a switch constructed in accordance with the present invention and showing four push-button plungers, one of whichmay be a release plunger,

Figure 2 is a top view, partly broken away, of a portion of a switch constructed in accordance with the present linvention and showing ve plungers,

Figure 3 is an enlarged view similar to Figure 2 but showing only the details of the center plunger,

Figure 4 is an end view, partly in cross section, taken along the line fi--tl of Figure 1 and looking in the direction of the appended'arrows,

Figure 5 is a view similar to kFigure 4 but showing the plunger in a depressed position, and

Figure 6 is a top View, partly in section, taken along the line 6-5 of Figure 1 illustrating a different form of the present invention. v

Referring more particularly to the drawing, there is shown in Figure l a-portion of a switch mechanism made in accordance with the present invention wherein a plurality of push-button plungers 2a, 2b, 2c, 2d are supported in a framework consisting of a lower frame member il, a cover member li and a pair of end supports (one shown). The iirst plunger 2c. s a release plunger (discussed in greater detail hereinafter). The remainder of the plungers 2b, 2c, 2d, etc. are contact operating plungers. A set of spring pile-up contacts l0, one set for each of the operating plungers, is actuated by a contact operating cam l2 on the respective operating plungers 2b, 2c, etc. These contact operating cams l2 are preferably made of an insulating material. Each of the plungers are normallybiased into an upward or non-operating position by a spring i3. Below the cover member 6, there is a channel member lli with an opening I6 therethrough for each of the plungers. Nested in the channel member is a pair of latch members i8 and 20 (see Fig. 6). These latch members lie in a common plane sideby-side and have a series of complementary apertures therein, one for each of the plungers. The complementary apertures are preferably in the form of semi-circular notches 22, 24 cut into the tact operating plungers 2b, 2c, etc.

edge of cach of the latch members I8, 20. The notches 22 in. one of the latch members I8 face the notches d. in the other of the latch members 2li. The notches in one of the latch members are adapted to be aligned with the corresponding notches .of the other member, however, they are normally spring 'biased into misalignment, We have also provided a retaining plate 25 which fits the upturned edges of the channel member le and serves to retain the latch members I3 and 2U in channel without binding. On each `of the plungers there is a frusto-conical latch operating cam 25- which, upon depressing one of the plungers, displaces the latch against the spring bias to align the complementary apertures. If the plunger is further depressed until the base of the cone 26 (i, e. the largest diameter) is below the latch members, the spring bias causes the latch members to close over the cam, locking the plunger in its depressed position. In such depressed position, the Acontact operating cam actuates the spring pile-up ycontacts Ill .as shown in Figure 5. When, as show-n lin Figure 6, the latch members or plates yI8 and 2'0 are common to all of the plungers, the plungers are interlocked. That is, the depressing of a second plunger will cause a previously locked plunger to be released.

It should 'be noted at this point that when the plungers are locked in the depressed or operating position, the respective latch members I8 and 2li lock. over the base of the cam 26 from opposite directions. With the spring bias on one latch plate I8 exerting its influence in one direction and 'the spring bias on the other latch plate 2t exerting its influence in the opposite direction, the two latch plates lock over the cam 25 substantially as shown on the second plunger 2b of Figure 2. Thus, while a shock or jolt on either one end oi the switch mechanism may cause one of the latch plates to move into an alignment with respect to the base of the cam 26, the other latch plate is not so displaced. Therefore, the depressed pilingers are not released by a severe jolt or shock to the mechanism from either end.

In some circumstances it may be desirable to be able to clear all lines from a remote position such as central control desk. Such a clearing of the line may be eiected by the inclusion of a solenoid or other electro-mechanical means 23 (Fig. 6) the armature of which is mechanically coupled to the latch plates IB and and which,

when excited, moves the latch plates I8 and 2U to a position where the complementary apertures are in alignment, releasing any plunger that may 'have been depressed. Thus, an executive may interrupt existing circuits to permit the issuance of important and urgent orders or instructions without the necessity of waiting until the line is free.

In Figures 2 and 3 there is illustrated a modified form of our invent-ion which provides means for oumulatively locking down a plurality of con- One of the common latch plates I8 has been replaced by a plurality of separate, independently operable latch segments 30h, 30o, 38d, etc., ea-ch with its own bias spring 32. In the arrangement shown in Figures 2 and 3 these bias springs 32 are anchored in the common latch plate 20 in the manner of a cantilever, the free end thereof pressing against one end of the latch segments Bill), 30e, 39d. also .proyides a biasing force for the common latch pla-te 20 in a direction opposite to that `applied to the latch segments. If any of the contact Thus the counteraction of the springs pressed, the subsequent pressing of another contact operating plunger will not cause the previously locked plunger to be released. Several plunger-s may be conveniently depressed, sequentially, Without the necessity of holding down previously locked plungers while depressing the subsequent ones as usually required on mechanisms having interlocked leys such as shown in Figure 6.

Since the depressing of subsequent plungers does not release previously locked plungers, means are provided ier releasing the locked plungers. For this purpose we have provided a release` plunger 2a which, so lar as the plunger itself is concerned, may be substantially identical with the Contact loperating plungers. Associated with the release plunger is a latch segment 36a which is similar to the other latch segments but differs from them. in that instead of being free to slide in the channel member Iii, it is secured thereto, for sample, by a pair of screws Each of the latch segments 3th, 30C, etc. associated with one of the contact operating piungers has a pin 56 which extends through a slot 38 in the upturned wall of the channel member It adjacent to each of the contact operating plungers. These slots 3s are so positioned with respect to the pins 3&5 as to limit the movement of the latch segments 3th, Eile, etc. in direction of the bias supplied by springs 32, but permit suihcient freedom of movement of the segments in the opposite direction to allow the notches in the segments to be aligned with and by the latch operating cams on the plungers. The channel member I=l is not rigidly secured in the structure, but rather has a limited freedom to move longitudinally. Therefore, when the release plunger 2c is depressed, the latch operating cams thereon move the common latch plate 2i? to the let, as viewed in Figures 2 and 3, to a position where the notches therein are in alignment with all of the respective plungers. Simultaneously therewith, the cam on the release plunger also moves the segment and hence the channel member I t. to the right. When the channel member Iii is `moved to the right, the latch segments Stb, 38e, 30d, etc must also move to the right since the pins 3B are butting against the left end of the respective slots Sii. It should now be apparent that when the release plunger is depressed any contact operating plunger that has been locked down would be released.

The openings i6 (shown in dotted lines in Figures 2 and 3) in the channel member Ill associated with each of the contact operating plungers need be only large enough to pass the largest diameter of the latch operating cam. They are made oval in shape to prevent interference with the latch operating cams 2G when the release button is pressed and the channel member I4 moves to the right as viewed in the drawings. However, the opening associated with the release plunger 2a should be aligned and coextensive with the notch in the latch segment 30a. With this arrangement, the release plunger may be locked in its depressed position, but it is held down only by accuses the common latch plate 2li, the channel member I4 (and, hence, all of the latch segments) being held in the right hand position by the channel member bearing on the latch operating cam of the release plunger. Since the common latch plate is moved to the left when any of the plungers are operated, the release plunger will be released upon depressing one of the contact operating plungers.

While the release plunger has been distinguished from the contact operating plungers in nomenclature, this has been purely for the sake of clarity in the description. There may well be a set of contacts operated by the release plunger` as shown in the drawings. These contacts may be used, for example, to control a busy or clear signal.

Although the switch mechanism of our present invention has been described as relating to an interofflce communication system, it should be f understood that the relationship was used for the purpose of illustration and was not intended to limit the use of the mechanism to such systems.

What is claimed is:

l. An electric circuit switching mechanism comprising a plurality of depressible contact operating plungers, means for locking said plungers in their depressed position, said means including a first latch plate and a second latch plate, said latch plates lying in a common plane and having complementary apertures, said apertures being normally biased into misalignment, cam means associated with each of said plungers for aligning at least one of said apertures in one of said latch plates with the complementary aperture in the other of said latch plates when one of said plungers is depressed, said latch plates being cooperatively engaged with said cam means to lock said plungers in their depressed position, and a release plunger having a cam means associated therewith which, upon operation of said release plunger, effects an alignment of all of said apertures whereby any contact operating plunger previously locked in its depressed position is released.

2. An electric circuit switching mechanism comprising a plurality of depressible contact operating plungers, means for locking said plungers in their depressed position, said means including a first latch means common to all of said plungers, a second latch means comprising an independent latch segment for each of said plungers, said first and second latch means being disposed in a common plane and having complementary apertures, said apertures being normally biased into misalignment, cam means associated with each of said plungers for aligning at least one of said apertures in one of said latch plates with the complementary aperture in the other of said latch plates when one of said plungers is depressed, said latch means being cooperatively engageable with said cam means to lock said plungers in their depressed position, and a release plunger having a cam means associated therewith which, upon operation of said release plunger, effects an alignment of all of said apertures whereby any contact operating plunger previously locked in its depressed position is released.

3. An electric circuit switching mechanism comprising a plurality of depressible contact operating plungers, a channel member having an opening for each of said plungers, a rst latch member lying in one half of said channel and common to all of said plungers, a second latch member lying in the other half oi said channel adjacent to said rst latch member, said latch members having complementary apertures normally biased into misalignment, cam means secured to each of said plungers, said cam means being adapted upon the depressing of one of said plungers to align at least one of said apertures in one of said latch plates with the complementary aperture in the other of said latch plates, said first and second latch means being cooperatively engageable with said cam means for locking said plungers in a depressed position, and a release plunger having a cam means thereon which, upon operation of said release plunger, effects an alignment of all of said apertures whereby any operating plunger previously locked in its depressed position is released.

4. An electric circuit switching mechanism comprising a plurality of depressible contact operating plungers, a channel member having an opening for each of said plungers, a rst latch member lying in one half of said channel and common to all of said plungers, a second latch member lying in the other half of said channel adjacent to said first latch member and being common to all of said plungers, said latch members having complementary apertures normally biased into misalignment, and cam means on each of said plungers, said cam means being adapted, upon the depressing of one of said plungers, to align said apertures, said first and second latch means being cooperatively engageable with said cam means for locking said plungers in a depressed position, the depressing of any one of said plungers effecting the release of any other plunger previously locked in a depressed position.

5. An electric circuit switching mechanism comprising a plurality of depressible contact operating plungers, a framework for supporting said plungers, means for locking said plungers in depressed position, said means including a rst and a second latch plate common to all of said plungers,`said latch plates lying in a common plane and having a plurality of complementary apertures each adapted to receive one of said plungers, said latch plates being normally biased in opposite directions to misalign said complementary apertures, and cam means secured to each of said plungers, said latch plates being slidably mounted in said framework whereby said plates may be moved to a position of alignment of said apertures under the influence of one of said cams when one of said plungers is depressed to permit the passage of said cam through said aperture, said latch plates being cooperatively engageable with said cams to lock said plunger in a depressed position.

6. The invention as set forth in claim 5 and characterized by the addition of a release plunger having a cam secured thereto which, upon operation of said release plunger, effects an alignment of said apertures releasing any Contact operating plunger previously locked in a depressed position.

7. The invention as set forth in claim 5 and characterized by the addition of means operable from a remote position to release any of said plungers locked in a depressed position.

8. The invention as set forth in claim 7 wherein said means includes an electro-mechanical device having an armature, said armature being mechanically coupled to said latch plates whereby, upon excitation of said device, said latch plates are moved to a position of alignment of said apertures, releasing any plunger previously depressed.

9. An electric circuit switching mechanism comprising a plurality of depressible contact operating plungers, a framework for supporting said plungers, means for cumulatively locking said plungers in an operating position, said means in cluding a first latch member mounted in said framework common to all of said plungers, a second latch member comprising an independent latch segment for each of the plungers, said rst and second latch members being disposed in a common plane and having complementary apertures adapted to receive each of said plungers, said latch members being,r normally biased in opposite directions to misalign said complementary apertures, cam means secured to each of said plungers, said latch members being slidably mounted in said framework whereby the aperture of one of said segments and the aperture of said rst latch member may be moved to a position of alignment under the influence of one of said cams when one of said plungers is depressed to permit the passage of said one of said cams through said aperture, said latch members being cooperatively engageable with said cam to lock said plunger in a depressed position, and a release plunger having a cam means secured thereto Which, upon operation of said release plunger, eiects an alignment of all of said apertures whereby any operating plunger previously locked in its depressed position is released.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,176,944 Bracket/t Mar. 28, 1916 1,271,378 Smith July 2, 1918 1,704,582 Stephenson Mar. 5, 1929 2,414,367 Johnson Jan. 14, 1947 2,451,150 Brian Oct. 12, 1948 

